Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6286612 | Progress in Neurobiology | 2011 | 26 Pages |
Swimming movements in the leech and lamprey are highly analogous, and lack homology. Thus, similarities in mechanisms must arise from convergent evolution rather than from common ancestry. Despite over 40 years of parallel investigations into this annelid and primitive vertebrate, a close comparison of the approaches and results of this research is lacking. The present review evaluates the neural mechanisms underlying swimming in these two animals and describes the many similarities that provide intriguing examples of convergent evolution. Specifically, we discuss swim initiation, maintenance and termination, isolated nervous system preparations, neural-circuitry, central oscillators, intersegmental coupling, phase lags, cycle periods and sensory feedback. Comparative studies between species highlight mechanisms that optimize behavior and allow us a broader understanding of nervous system function.
Research highlightsⶠThis review compares neural mechanisms underlying swimming in leeches and lampreys. ⶠFocus is on swim initiation, maintenance, termination, and swim pattern generation. ⶠAnalogous swim movements have led to convergent evolution to optimize behavior. ⶠSignificant differences in intersegmental coupling and rhythm generation exist.